The present invention relates to a sheet feeding device for a printer, copier, facsimile apparatus, printer or similar image forming apparatus.
An image forming apparatus of the kind described includes an image reader for reading a document image, and a sheet supply mechanism for feeding a recording sheet to reproduce the document image thereon. The image reader and sheet supply mechanism are each provided with a sheet feeding device for feeding documents or sheets one by one by separating them. Usually, the sheet feeding device includes a pick-up roller for picking up documents or sheets, a teed roller to which the documents or sheets picked up are fed, and a blade pressed against the feed roller at the edge thereof. The documents or sheets driven by the pick-up roller are brought to between the feed roller and the edge of the blade to be separated one by one.
Since the blade is made of an elastic material, it bends with the edge thereof pressing against the feed roller. Therefore, the angle between the blade and the feed roller for transporting documents of sheets is reduced by an angle corresponding to the bend of the blade. As a result, a force acting on, among two documents or sheets fed, the second document or sheet due to the force of the blade is greater than a force preventing the second document or sheet from being fed, i.e., separating the first sheet from the second sheet. As a result, the second sheet is strongly pressed against the first sheet, obstructing the separation of the first sheet. Moreover, in the case of two-sided documents each carrying an image on both sides thereof, they strongly rub against each other to degrade their images.